SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca9478b5ad69e37d1463a89afc9a01698ea4ff9327603ff38b64fdfc2642617d' 
  AND token = 'JqvQ0DADXi/9KhiEER0gGYzvGDYVYvguJh0tmtbJgN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}